#define _CRT_SECURE_NO_WARNINGS 1
#include <cmath>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include<math.h>
#include<stdlib.h>
#include<stdio.h>
#include<unordered_map>
#include<queue>
#include<stack>
#include <functional>
#include <memory>
using namespace std;

class Solution {
public:
    int numDecodings(string s) {
        int n = s.size();
        vector<int> dp(n + 1);
        dp[0] = 1;
        dp[1] = s[1 - 1] != '0';
        for (int i = 2; i <= n; i++)
        {
            if (s[i - 1] != '0') dp[i] += dp[i - 1];
            int t = (s[i - 2] - '0') * 10 + s[i - 1] - '0';
            if (t >= 10 && t <= 26) dp[i] += dp[i - 2];
        }
        return dp[n];
    }
};

int main()
{
    vector<int> in(30, -1);
	return 0;
}